Intelligence and RIAA
 

Keith G wrote:
"Nick Gorham" wrote in message
...

Keith G wrote:


No, if you want a chuckle - I have crapped copious amounts of blood
this morning trying to get my Nuvistor laptop to record from a pair
of mics. So far, I have finally managed to get a *stereo* recording
(not easy) but have also managed to swap the previous machine's
intermittent 'heartbeat' for a consistent/continual loud (in the
Plowie sense) *buzz*...!!

And no, I can't post a sample because my FTP programme's grace period
expired today! (Fekkin' telling me summat it is....)





Go to the command prompt and type

ftp myserver.pipex.net

Should do the job.



No, all I got was 'unknown host'...??





Err, I meant that you should replace the myserver.pipex.net with your
actual servers name. You must have specified it when you setup the ftp
client that isn't working.

--
Nick

Intelligence and RIAA
 

dave weil said:

I define what I want the sound to be and to do

As long as you don't define it for anyone else.
Oh wait, that's pretty much what you did.

Nonconformity is a cardinal sin in the Hive. But you knew that.




--

Krooscience: The antidote to education, experience, and excellence.

Intelligence and RIAA
 

In article ,
Patrick Turner wrote:

Gerry wrote:

What the hell is "bodge"????

Andre will have his answer, but when he or someone else uses the term
they mean you have to make the signal from the microphone through to the
speaker via vinyl go through a roller coaster ride of "enfrightenment".

Why can't they just record the mic signal after amplifying with a linear
amp,
cutting record with a linear amplitude amp, and having playback
with a flat amp?

What are a few of the reasons? I assume the main reason the RIAA
recording curve shelves down the high frequency groove amplitude is
because if the high frequencies weren't reduced while cutting the record
the groove velocity, and acceleration, at high frequencies would be too
much for the playback pickup to cope with. Cutting the high frequency
amplitude during recording also would reduce the "pinch" effect. Maybe
an expert can tell us the reasons why the high frequency amplitude is
shelved down when cutting a record following the RIAA recording curve?
The down side is that a "bodge" in the form of a complementary high
frequency amplitude boost must be applied during playback, which
accentuates the high frequency noise.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

Intelligence and RIAA
 

"Nick Gorham" wrote in message
...
Keith G wrote:
"Nick Gorham" wrote in message
...

Keith G wrote:


No, if you want a chuckle - I have crapped copious amounts of blood
this morning trying to get my Nuvistor laptop to record from a pair
of mics. So far, I have finally managed to get a *stereo* recording
(not easy) but have also managed to swap the previous machine's
intermittent 'heartbeat' for a consistent/continual loud (in the
Plowie sense) *buzz*...!!

And no, I can't post a sample because my FTP programme's grace
period expired today! (Fekkin' telling me summat it is....)





Go to the command prompt and type

ftp myserver.pipex.net

Should do the job.



No, all I got was 'unknown host'...??





Err,


'Err'...??

Intelligence and RIAA
 

John Byrns wrote:
In article ,
Patrick Turner wrote:


Gerry wrote:

What the hell is "bodge"????

Andre will have his answer, but when he or someone else uses the term
they mean you have to make the signal from the microphone through to the
speaker via vinyl go through a roller coaster ride of "enfrightenment".

Why can't they just record the mic signal after amplifying with a linear
amp,
cutting record with a linear amplitude amp, and having playback
with a flat amp?


What are a few of the reasons? I assume the main reason the RIAA
recording curve shelves down the high frequency groove amplitude is
because if the high frequencies weren't reduced while cutting the record
the groove velocity, and acceleration, at high frequencies would be too
much for the playback pickup to cope with. Cutting the high frequency
amplitude during recording also would reduce the "pinch" effect. Maybe
an expert can tell us the reasons why the high frequency amplitude is
shelved down when cutting a record following the RIAA recording curve?
The down side is that a "bodge" in the form of a complementary high
frequency amplitude boost must be applied during playback, which
accentuates the high frequency noise.

You have that graph upside down. HF is boosted for disc cutting
and reduced on playback to reduce noise (among other reasons).

Not many people know that preemphasis is also an option for CDs.

--
Eiron.

May contain traces of irony.

Intelligence and RIAA
 

John Byrns wrote:
In article ,
Patrick Turner wrote:

Gerry wrote:
What the hell is "bodge"????
Andre will have his answer, but when he or someone else uses the term
they mean you have to make the signal from the microphone through to the
speaker via vinyl go through a roller coaster ride of "enfrightenment".

Why can't they just record the mic signal after amplifying with a linear
amp,
cutting record with a linear amplitude amp, and having playback
with a flat amp?

What are a few of the reasons? I assume the main reason the RIAA
recording curve shelves down the high frequency groove amplitude is
because if the high frequencies weren't reduced while cutting the record
the groove velocity, and acceleration, at high frequencies would be too
much for the playback pickup to cope with. Cutting the high frequency
amplitude during recording also would reduce the "pinch" effect. Maybe
an expert can tell us the reasons why the high frequency amplitude is
shelved down when cutting a record following the RIAA recording curve?
The down side is that a "bodge" in the form of a complementary high
frequency amplitude boost must be applied during playback, which
accentuates the high frequency noise.


Regards,

John Byrns

The reason the HF is turned down by the RIAA EQ is to reduce surface
noise. LPs are essentially a constant velocity system, so higher
frequencies can be boosted on record as their amplitude on the record is
reducing, and cut back on playback, together with the surface noise.

Low frequencies are turned down by the RIAA EQ to reduce their amplitude
so as to ensure the 20 minutes or so playing time per side. If they
were cut flat, the increasing amplitude would mean that much more space
would have to be left between grooves, reducing the playing time very
significantly.

This is an example of " necessity being the mother of invention" It was
necessary to reduce low frequency amplitude, so also deriving the
benefit of reducing HF surface noise too.

This principle was applied later to FM radio, where an HF
preemphasis/deemphasis reduces noise at the expense of HF headroom.

S.

--
http://audiopages.googlepages.com

Intelligence and RIAA
 

In article ,
Eiron wrote:

John Byrns wrote:
In article ,
Patrick Turner wrote:


Gerry wrote:

What the hell is "bodge"????

Andre will have his answer, but when he or someone else uses the term
they mean you have to make the signal from the microphone through to the
speaker via vinyl go through a roller coaster ride of "enfrightenment".

Why can't they just record the mic signal after amplifying with a linear
amp,
cutting record with a linear amplitude amp, and having playback
with a flat amp?


What are a few of the reasons? I assume the main reason the RIAA
recording curve shelves down the high frequency groove amplitude is
because if the high frequencies weren't reduced while cutting the record
the groove velocity, and acceleration, at high frequencies would be too
much for the playback pickup to cope with. Cutting the high frequency
amplitude during recording also would reduce the "pinch" effect. Maybe
an expert can tell us the reasons why the high frequency amplitude is
shelved down when cutting a record following the RIAA recording curve?
The down side is that a "bodge" in the form of a complementary high
frequency amplitude boost must be applied during playback, which
accentuates the high frequency noise.

You have that graph upside down. HF is boosted for disc cutting
and reduced on playback to reduce noise (among other reasons).

No, I have the graph exactly the correct way around. The RIAA disk
cutting curve reduces the high frequency groove amplitude by roughly 12
dB using a shelving equalizer with time constants of 318.3 usec. and 75
usec. You are the one that has his RIAA groove amplitude graph upside
down, I suggest doing a little homework before making further comment so
as not to embarrass yourself in public.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

Intelligence and RIAA
 

In article ,
Serge Auckland wrote:

John Byrns wrote:
In article ,
Patrick Turner wrote:

Gerry wrote:
What the hell is "bodge"????
Andre will have his answer, but when he or someone else uses the term
they mean you have to make the signal from the microphone through to the
speaker via vinyl go through a roller coaster ride of "enfrightenment".

Why can't they just record the mic signal after amplifying with a linear
amp,
cutting record with a linear amplitude amp, and having playback
with a flat amp?

What are a few of the reasons? I assume the main reason the RIAA
recording curve shelves down the high frequency groove amplitude is
because if the high frequencies weren't reduced while cutting the record
the groove velocity, and acceleration, at high frequencies would be too
much for the playback pickup to cope with. Cutting the high frequency
amplitude during recording also would reduce the "pinch" effect. Maybe
an expert can tell us the reasons why the high frequency amplitude is
shelved down when cutting a record following the RIAA recording curve?
The down side is that a "bodge" in the form of a complementary high
frequency amplitude boost must be applied during playback, which
accentuates the high frequency noise.

The reason the HF is turned down by the RIAA EQ is to reduce surface
noise.

No, you have that exactly backwards, the RIAA recording curve reduces
the groove amplitude at high frequencies, requiring a complimentary high
frequency boost in playback, which increases the effects of surface
noise.

LPs are essentially a constant velocity system, so higher
frequencies can be boosted on record as their amplitude on the record is
reducing, and cut back on playback, together with the surface noise.

No, No, a thousand times NO, LP's are essentially a constant amplitude
system with the high frequency groove amplitude shelved down by
approximately 12 dB, LP's are nowhere near a constant velocity system.
Viewed as a constant velocity system approximately 38 dB of equalization
would have to be applied. 12 dB vs. 38 dB makes LP's essentially a
constant amplitude system.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

Intelligence and RIAA
 

On Mon, 14 May 2007 09:21:32 -0500, John Byrns
wrote:

In article ,
Serge Auckland wrote:

John Byrns wrote:
In article ,
Patrick Turner wrote:

Gerry wrote:
What the hell is "bodge"????
Andre will have his answer, but when he or someone else uses the term
they mean you have to make the signal from the microphone through to the
speaker via vinyl go through a roller coaster ride of "enfrightenment".

Why can't they just record the mic signal after amplifying with a linear
amp,
cutting record with a linear amplitude amp, and having playback
with a flat amp?

What are a few of the reasons? I assume the main reason the RIAA
recording curve shelves down the high frequency groove amplitude is
because if the high frequencies weren't reduced while cutting the record
the groove velocity, and acceleration, at high frequencies would be too
much for the playback pickup to cope with. Cutting the high frequency
amplitude during recording also would reduce the "pinch" effect. Maybe
an expert can tell us the reasons why the high frequency amplitude is
shelved down when cutting a record following the RIAA recording curve?
The down side is that a "bodge" in the form of a complementary high
frequency amplitude boost must be applied during playback, which
accentuates the high frequency noise.

The reason the HF is turned down by the RIAA EQ is to reduce surface
noise.

No, you have that exactly backwards, the RIAA recording curve reduces
the groove amplitude at high frequencies, requiring a complimentary high
frequency boost in playback, which increases the effects of surface
noise.


This is news to me, and a thousand audio designers for the last
seventy-odd years.

LPs are essentially a constant velocity system, so higher
frequencies can be boosted on record as their amplitude on the record is
reducing, and cut back on playback, together with the surface noise.

No, No, a thousand times NO, LP's are essentially a constant amplitude
system with the high frequency groove amplitude shelved down by
approximately 12 dB, LP's are nowhere near a constant velocity system.
Viewed as a constant velocity system approximately 38 dB of equalization
would have to be applied. 12 dB vs. 38 dB makes LP's essentially a
constant amplitude system.


LPs are a combination of constant velocity and constant amplitude,
depending on the frequency range.

d

--
Pearce Consulting
http://www.pearce.uk.com

Intelligence and RIAA
 

John Byrns wrote:

In article ,
Eiron wrote:

You have that graph upside down. HF is boosted for disc cutting
and reduced on playback to reduce noise (among other reasons).


No, I have the graph exactly the correct way around. The RIAA disk
cutting curve reduces the high frequency groove amplitude by roughly 12
dB using a shelving equalizer with time constants of 318.3 usec. and 75
usec. You are the one that has his RIAA groove amplitude graph upside
down, I suggest doing a little homework before making further comment so
as not to embarrass yourself in public.

I suggest doing a little homework before making further comment
so as not to embarrass yourself even more in public.
And just to get you started:
http://en.wikipedia.org/wiki/RIAA_equalization

--
Eiron.

May contain traces of irony.